A technique is known which makes a database redundant among a plurality of information processing devices. For example, a certain document discloses a technique in which a master server includes a session table where information for a session is registered and a replica server duplicates the session table of the master server.
However, in a case where information for connection of information processing devices is registered in a database and communication which is performed to synchronize the database stops due to communication obstacles, the connection between the information processing devices might not be regularly established.
Japanese Laid-open Patent Publication No. 2014-48969 is an example of the related art.